A soldering technology in which by applying a solder paste to the land formed on the substrate, mounting the electronic components on the solder-paste-applied land of the substrate and melting the solder paste, the soldering is carried out has been conventionally used.
If a mechanical strength for fixation is required when mounting the electronic components using such a method, an amount of solder may be in short supply by only the solder paste applied to the land.
Thus, a technology for supplementing the solder by mounting a chipped solder, which is so called as “solder piece”, on the land in addition to the solder paste has been proposed (see, for example, Patent Document 1).